Reinforced electrode leads and methods for manufacturing the same

ABSTRACT

An exemplary electrode lead includes a flexible body formed of a flexible insulating material and that comprises a fantail region that connects to a cochlear implant configured to be implanted within a recipient and that extends to a ground electrode located toward a proximal end of the electrode lead, an electrode contact disposed on a side of the flexible body, a coiled electrode wire provided within the flexible body so as to extend along a length of the flexible body and electrically connect the electrode contact to a signal source, and a coiled reinforcing element provided within the flexible body so as to extend together with the coiled electrode wire along the length of the flexible body. The coiled reinforcing element may only be provided within a proximal portion of the electrode lead. Corresponding methods of manufacturing an electrode lead are also described.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 17/258,922, filed Jan. 8, 2021, which is a U.S.National Stage Application under 35 U.S.C. § 371 of InternationalApplication No. PCT/US2018/043316, filed on Jul. 23, 2018, each of whichis hereby incorporated by reference in its entirety.

BACKGROUND INFORMATION

Cochlear implant systems are used to provide, restore, and/or improvethe sense of hearing to recipients with severe or profound hearing loss.A key component of a cochlear implant system is an electrode lead thatis inserted into a cochlea of the recipient in a delicate surgicalprocedure referred to herein as an “insertion procedure.” A typicalelectrode lead includes conductive wires that are provided within anelectrode lead body formed of an insulating biocompatible material.

To facilitate insertion of the electrode lead during the insertionprocedure, the electrode lead is typically formed to be flexible so thatthe electrode lead can conform to the spiral shape of the human cochleawhen implanted in the recipient. Such flexibility is typically achievedby using soft silicone tubing for the electrode lead body and very thinconductive wires (e.g., 20-25 μm in diameter). However, these conductivewires are fragile, and the soft silicone tubing used for the electrodelead body is, in certain circumstances, not strong enough by itself tosufficiently protect the conductive wires. As a result, the conductivewires may be broken or damaged during manufacturing, packaging,handling, the insertion procedure, and/or impact (e.g., from a traumaticinjury to the head of the recipient).

U.S. Pat. No. 3,760,812 (“Timm”) discloses implantable spiral woundstimulation electrodes. For example, Timm discloses a stimulationelectrode that includes conductor wires and spacer strands that arewrapped helically around a flexible cylindrical insulative core suchthat the spacer strands are provided between adjacent winds of theconductor wires. In Timm, the conductor wires and alternating spacerstrands are maintained in a desired relationship by insulative strandsthat are helically wound in the opposite direction from the conductorwires and the spacer strands, that have substantially the same spacingas the conductor wires and the spacer strands, and that are interwovenwith the conductor wires and the spacer strands.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments and are a partof the specification. The illustrated embodiments are merely examplesand do not limit the scope of the disclosure. Throughout the drawings,identical or similar reference numbers designate identical or similarelements.

FIG. 1 illustrates an exemplary cochlear implant system according toprinciples described herein.

FIG. 2 illustrates a schematic structure of the human cochlea accordingto principles described herein.

FIG. 3 illustrates exemplary components of the cochlear implant systemthat are configured to be implanted in a recipient according toprinciples described herein.

FIG. 4 illustrates an enlarged fantail region of an exemplary electrodelead having a coiled reinforcing element according to principlesdescribed herein.

FIG. 5 illustrates an exemplary cross section of the electrode leadshown in FIG. 4 that is taken along line 5 in FIG. 4 according toprinciples described herein.

FIGS. 6-9 illustrate enlarged fantail regions of additional exemplaryelectrode leads according to principles described herein.

FIGS. 10 and 11 show exemplary methods for manufacturing a reinforcedelectrode lead having a coiled reinforcing element according toprinciples described herein.

DETAILED DESCRIPTION

Reinforced electrode leads and methods for manufacturing the same aredescribed herein. As will be described in more detail below, anexemplary electrode lead described herein includes a flexible bodyformed of a flexible insulating material and an electrode contactdisposed on a side of the flexible body. The electrode lead furtherincludes a coiled electrode wire provided within the flexible body so asto extend along a length of the flexible body and electrically connectthe electrode contact to a signal source. The electrode lead furtherincludes a coiled reinforcing element provided within the flexible bodyso as to extend together with the coiled electrode wire along the lengthof the flexible body. A winding direction of the coiled electrode wireis opposite a winding direction of the coiled reinforcing element. Awinding pitch of the coiled electrode wire is smaller than a windingpitch of the coiled reinforcing element.

For example, the coiled electrode wire may be wound in a clockwisedirection and the coiled reinforcing element may be wound in acounterclockwise direction, or vice versa. Such a configuration helpsprotect the coiled electrode wire from damage in circumstances wheretorsion is provided in a direction opposite to the winding direction ofthe coiled electrode wire. Typically, when torsion is provided to acoiled electrode wire is such a direction, the coiled electrode wire hasa propensity to kink, which could damage or break the coiled electrodewire. However, when the coiled reinforcing element is wound in a windingdirection opposite the winding direction of the coiled electrode wire,the coiled reinforcing element provides a resistive force that causesthe electrode lead to resist being twisted in the direction opposite tothe winding direction of the coiled electrode wire. As such, coiledreinforcing elements such as those described herein help prevent damagethat may be caused due to kinking of the coiled electrode wire.

Configuring the winding pitch of the coiled electrode wire to be smallerthan the winding pitch of the coiled reinforcing element also helpsprevent damage to the coiled electrode wire. For example, such aconfiguration helps prevent damage to the coiled electrode wire when theelectrode lead is in tension (i.e., when stretched) because therelatively larger winding pitch of the coiled reinforcing element causesthe coiled reinforcing element to tighten earlier than the coiledelectrode wire. As a result, the coiled reinforcing element is able toabsorb tensile stress that would otherwise be applied to the coiledelectrode wire, thus protecting the coiled electrode wire from beingdamaged. In contrast, if a coiled reinforcing element has the same orsmaller winding pitch as a coiled electrode wire, the coiled electrodewire may tighten earlier than the coiled reinforcing element when theelectrode lead is stretched. As a result, the coiled electrode wire maybe subjected to all or most of the tensile stress instead of the coiledreinforcing element, which could cause damage to the coiled electrodewire if the coiled electrode wire is stretched to a breaking point.Accordingly, by making a winding pitch of coiled reinforcing elementssuch as those described herein larger than a winding pitch of a coiledelectrode wire, the coiled reinforcing elements are configured toprotect the coiled electrode wire from being damaged.

The electrode leads described herein may provide various benefits tocochlear implant recipients, as well as to surgeons and others involvedwith insertion procedures. For example, because the electrode leadsdescribed herein include one or more reinforcing elements, the electrodeleads are less susceptible to being damaged during packaging, transport,and/or handling, for example, by support staff prior to the insertionprocedure. In addition, the electrode leads described herein are lesssusceptible to being damaged or broken during an insertion procedurecompared with conventional electrode leads. Moreover, electrode leadssuch as those described herein have increased mechanical strength at afantail region as compared with conventional electrode leads, whichresults in a decreased likelihood that the electrode lead will bedamaged due to, for example, an impact to the recipient's head where theelectrode lead is connected to an implanted cochlear implant.Accordingly, cochlear implant systems that use electrode leads such asthose described herein are more robust and potentially have a longeroperational life than cochlear implant systems that use conventionalelectrode leads.

Various embodiments will now be described in more detail with referenceto the figures. The disclosed apparatus and methods may provide one ormore of the benefits mentioned above and/or various additional and/oralternative benefits that will be made apparent herein.

FIG. 1 illustrates an exemplary cochlear implant system 100. As shown,cochlear implant system 100 may include a microphone 102, a soundprocessor 104, a headpiece 106 having a coil disposed therein, acochlear implant 108, and an electrode lead 110. Electrode lead 110 mayinclude an array of electrodes 112 disposed on a distal portion ofelectrode lead 110 and that are configured to be inserted into thecochlea to stimulate the cochlea after the distal portion of electrodelead 110 is inserted into the cochlea. It will be understood that one ormore other electrodes (e.g., including a ground electrode, notexplicitly shown in FIG. 1 ) may also be disposed on other parts ofelectrode lead 110 (e.g., on a proximal portion of electrode lead 110)to, for example, provide a current return path for stimulation currentgenerated by electrodes 112 and to remain external to the cochlea afterelectrode lead 110 is inserted into the cochlea. Various embodiments ofelectrode lead 110 will be described herein. Additional or alternativecomponents may be included within cochlear implant system 100 as mayserve a particular implementation. For example, a pre-curved electrodelead and/or a straight electrode lead may alternatively be used inconnection with cochlear implant 108.

As shown, cochlear implant system 100 may include various componentsconfigured to be located external to a recipient including, but notlimited to, microphone 102, sound processor 104, and headpiece 106.Cochlear implant system 100 may further include various componentsconfigured to be implanted within the recipient including, but notlimited to, cochlear implant 108 and electrode lead 110.

Microphone 102 may be configured to detect audio signals presented tothe user. Microphone 102 may be implemented in any suitable manner. Forexample, microphone 102 may include a microphone that is configured tobe placed within the concha of the ear near the entrance to the earcanal, such as a T-MIC™ microphone from Advanced Bionics. Such amicrophone may be held within the concha of the ear near the entrance ofthe ear canal by a boom or stalk that is attached to an ear hookconfigured to be selectively attached to sound processor 104.Additionally or alternatively, microphone 102 may be implemented by oneor more microphones disposed within headpiece 106, one or moremicrophones disposed within sound processor 104, one or morebeam-forming microphones, and/or any other suitable microphone as mayserve a particular implementation.

Sound processor 104 (i.e., one or more components included within soundprocessor 104) may be configured to direct cochlear implant 108 togenerate and apply electrical stimulation (also referred to herein as“stimulation current”) representative of one or more audio signals(e.g., one or more audio signals detected by microphone 102, input byway of an auxiliary audio input port, input by way of a device like theClinical Programming Interface (“CPI”) device from Advanced Bionics,etc.) to one or more stimulation sites associated with an auditorypathway (e.g., the auditory nerve) of the recipient. Exemplarystimulation sites include, but are not limited to, one or more locationswithin the cochlea, the cochlear nucleus, the inferior colliculus,and/or any other nuclei in the auditory pathway. To this end, soundprocessor 104 may process the one or more audio signals in accordancewith a selected sound processing strategy or program to generateappropriate stimulation parameters for controlling cochlear implant 108.Sound processor 104 may be housed within any suitable housing (e.g., abehind-the-ear (“BTE”) unit, a body worn device, headpiece 106, and/orany other sound processing unit as may serve a particularimplementation).

In some examples, sound processor 104 may wirelessly transmitstimulation parameters (e.g., in the form of data words included in aforward telemetry sequence) and/or power signals to cochlear implant 108by way of a wireless communication link 114 between headpiece 106 andcochlear implant 108 (e.g., a wireless link between a coil disposedwithin headpiece 106 and a coil physically coupled to cochlear implant108). It will be understood that communication link 114 may include abi-directional communication link and/or one or more dedicateduni-directional communication links.

Headpiece 106 may be communicatively coupled to sound processor 104 andmay include an external antenna (e.g., a coil and/or one or morewireless communication components) configured to facilitate selectivewireless coupling of sound processor 104 to cochlear implant 108.Headpiece 106 may additionally or alternatively be used to selectivelyand wirelessly couple any other external device to cochlear implant 108.To this end, headpiece 106 may be configured to be affixed to therecipient's head and positioned such that the external antenna housedwithin headpiece 106 is communicatively coupled to a correspondingimplantable antenna (which may also be implemented by a coil and/or oneor more wireless communication components) included within or otherwiseassociated with cochlear implant 108. In this manner, stimulationparameters and/or power signals may be wirelessly transmitted betweensound processor 104 and cochlear implant 108 via a communication link114 (which may include a bi-directional communication link and/or one ormore dedicated uni-directional communication links as may serve aparticular implementation).

Cochlear implant 108 may include any type of implantable stimulator thatmay be used in association with the systems and methods describedherein. For example, cochlear implant 108 may be implemented by animplantable cochlear stimulator. In some alternative implementations,cochlear implant 108 may include a brainstem implant and/or any othertype of cochlear implant that may be implanted within a recipient andconfigured to apply stimulation to one or more stimulation sites locatedalong an auditory pathway of a recipient.

In some examples, cochlear implant 108 may be configured to generateelectrical stimulation representative of an audio signal processed bysound processor 104 (e.g., an audio signal detected by microphone 102)in accordance with one or more stimulation parameters transmittedthereto by sound processor 104. Cochlear implant 108 may be furtherconfigured to apply the electrical stimulation to one or morestimulation sites (e.g., one or more intracochlear regions) within therecipient via electrodes 112 disposed along electrode lead 110. In someexamples, cochlear implant 108 may include a plurality of independentcurrent sources each associated with a channel defined by one or more ofelectrodes 112. In this manner, different stimulation current levels maybe applied to multiple stimulation sites simultaneously by way ofmultiple electrodes 112.

FIG. 2 illustrates a schematic structure of the human cochlea 200 intowhich electrode lead 110 may be inserted. As shown in FIG. 2 , cochlea200 is in the shape of a spiral beginning at a base 202 and ending at anapex 204. Within cochlea 200 resides auditory nerve tissue 206, which isdenoted by Xs in FIG. 2 . The auditory nerve tissue 206 is organizedwithin the cochlea 200 in a tonotopic manner. Relatively low frequenciesare encoded at or near the apex 204 of the cochlea 200 (referred to asan “apical region”) while relatively high frequencies are encoded at ornear the base 202 (referred to as a “basal region”). Hence, electricalstimulation applied by way of electrodes disposed within the apicalregion (i.e., “apical electrodes”) may result in the recipientperceiving relatively low frequencies and electrical stimulation appliedby way of electrodes disposed within the basal region (i.e., “basalelectrodes”) may result in the recipient perceiving relatively highfrequencies. The delineation between the apical and basal electrodes ona particular electrode lead may vary depending on the insertion depth ofthe electrode lead, the anatomy of the recipient's cochlea, and/or anyother factor as may serve a particular implementation.

FIG. 3 illustrates an exemplary depiction of components of cochlearimplant system 100 that are configured to be implanted in a recipient.For example, FIG. 3 shows cochlear implant 108 communicatively coupledto electrode lead 110 with electrodes 112 disposed along electrode lead110. FIG. 3 also shows a ground electrode 302 disposed on a proximalportion of lead 110 and that is configured to provide a return path forcurrent delivered to electrodes 112. As shown in FIG. 3 , electrode lead110 includes a fantail region 304 provided towards a proximal end ofelectrode lead 110, where electrode lead 110 connects to cochlearimplant 108. Electrode lead 110 also includes a distal region 306 thatis provided towards a distal end of electrode lead 110 and that isconfigured to be inserted in the cochlea of a recipient. In someinstances, fantail region 304 may generally be considered as a region ofelectrode lead 110 that is provided between ground electrode 302 andcochlear implant 108. Distal region 306 may generally be considered as aregion of electrode lead 110 that is provided between a most proximalelectrode included in electrodes 112 and a distal end of electrode lead110.

Cochlear implant 108 is configured to provide electrical stimulation tothe one or more stimulation sites by way of a plurality of electrodewires (not shown in FIG. 3 ) that are provided within electrode lead 110and that electrically connect electrodes 112 to one or more signalsources within cochlear implant 108. The electrode wires may be formedof any suitable conductive material. In certain examples, the electrodewires may be formed of coiled 20-25 μm metal wires that are fragile andthat may easily be broken or get damaged during packaging, handling,surgery, etc. The electrode wires are particularly susceptible to beingbroken or damaged in fantail region 304. This is in part because fantailregion 304 is located on an outer surface of the skull when implantedwithin a recipient whereas the rest of electrode lead 110 is locatedunder the skull. This causes the mechanical strength of the electrodewires to be significantly changed in fantail region 304 (i.e., a stressgradient of the electrode wires in fantail region 304 is relativelyhigher than in other regions). Damage to the electrode wires included inelectrode lead 110 may result in either sub-optimal function or loss offunction of cochlear implant system 100.

As will be described herein, to protect electrode wires within electrodelead 110 from breaking or otherwise being damaged, electrode lead 110may include one or more coiled reinforcing elements configured tomechanically strengthen electrode lead 110. Coiled reinforcing elementssuch as such as those described herein may be configured in any manneras may suit a particular implementation. For example, a coiledreinforcing element may include a coiled wire, fiber, strand, ribbon,group of wires, group of fibers, group of strands, group of ribbons,etc., or any suitable combination thereof. A coiled reinforcing elementmay be made of any suitable material as may serve a particularimplementation. For example, a coiled reinforcing element may be formedof a biocompatible polymer wire, fiber, strand, or ribbon. Examples ofbiocompatible polymers that may be used to form a coiled reinforcingelement include polyethylene, ultra-high-modulus polyethylene (UHMPE),polyether ether ketone (PEEK), polyamide (nylon), etc. Various exemplarycoiled reinforcing elements that may be used to reinforce electrode lead110 will now be described with reference to FIGS. 4-9 .

FIG. 4 shows an enlarged view of fantail region 304 of electrode lead110 that includes a plurality of coiled reinforcing elements 402(“coiled reinforcing elements 402”), a plurality of coiled electrodewires 404 (“coiled electrode wires 404”), and a coiled grounding wire406 that connects to ground electrode 302. Coiled reinforcing elements402, coiled electrode wires 404, and coiled grounding wire 406 areprovided within a flexible body 408.

Flexible body 408 may be formed of any suitable biocompatible insulatingmaterial that is sufficiently flexible to bend during the insertionprocedure. In certain examples, flexible body 408 is formed of silicone.However, any other suitable insulating material may be used in certainimplementations. Although only a portion of flexible body 408 is shownin FIG. 4 , it is understood that flexible body 408 may be providedalong the entire length of electrode lead 110.

Coiled reinforcing elements 402 may include any number of reinforcingelements as may serve a particular implementation. For example, in theexample of FIG. 4 , coiled reinforcing elements 402 include fivereinforced reinforcing elements. As shown, coiled reinforcing elements402 may be bundled together and helically wound along a length offlexible body 408. As such, coiled reinforcing elements 402 form aplurality of helically formed groups of windings extending withinflexible body 408 along the length of flexible body 408. In FIG. 4 ,winding group 410 represents one group of windings included in theplurality of helically formed groups of windings of coiled reinforcingelements 402. Each winding group included in the plurality of helicallyformed groups of windings of coiled reinforcing elements 402 may bespaced apart from a successive winding group by approximately the sameamount along the length of flexible body 408.

Coiled electrode wires 404 may include any number of electrode wires(e.g., sixteen) as may serve a particular implementation. As shown,coiled electrode wires 404 are also bundled together and helically woundalong the length of flexible body 408. As such, coiled electrical wires404 form a plurality of helically formed groups of windings extendingwithin flexible body 408 along the length of flexible body 408. Windinggroup 412 represents one group of windings included in the plurality ofhelically formed groups of windings of coiled electrode wires 404. Eachwinding group included in the plurality of helically formed groups ofwindings of coiled electrode wires 404 may be spaced apart from asuccessive winding group by approximately the same amount along thelength of flexible body 408.

As shown in FIG. 4 , a winding pitch 414 of coiled electrode wires 404is smaller than a winding pitch 416 of coiled reinforcing elements 402.With such a configuration, when electrode lead 110 is in tension, therelatively larger winding pitch of coiled reinforcing elements 402causes coiled reinforcing elements 402 to tighten earlier than coiledelectrode wires 404, thus protecting coiled electrode wires 404 frombeing damaged.

As used herein, a “winding pitch” refers to a distance betweensuccessive windings included a plurality of helically formed windingsformed out of the same reinforcing element or wire. For example, acoiled electrode wire may include a plurality of helically formedwindings extending along a length of a flexible body. The plurality ofhelically formed windings of the coiled electrode wire may include afirst winding, a second winding, and a third winding arrangedsuccessively in that order along the length of the flexible body. Insuch an example, the winding pitch of the coiled electrode wire may be adistance between successive windings (e.g., the first winding and thesecond winding) included in the plurality of helically formed windings.

Similarly, a winding pitch of a coiled reinforcing element maycorrespond to a distance between successive windings (e.g., a firstwinding and a second winding) included in a plurality of helicallyformed windings of the coiled reinforcing element. In certain examples,successive windings of a coiled reinforcing element may be directlyadjacent to one another. For example, the first winding may be directlyadjacent to the second winding and the second winding may be directlyadjacent to a third winding along the length of the flexible body.Alternatively, in certain examples described herein, one or morewindings of an additional coiled reinforcing element may be providedbetween, for example, the first winding and the second winding of thecoiled reinforcing element.

In the example shown in FIG. 4 , winding pitch 414 corresponds to adistance between successive windings groups of coiled electrode wires404 that are directly adjacent to one another (e.g., winding group 412and the successive winding group of coiled electrode wires 404 directlyto the right of winding 412). Likewise, winding pitch 416 corresponds toa distance between successive windings groups of coiled reinforcingelements 402 that are directly adjacent to one another (e.g., windinggroup 410 and the successive winding group included in coiledreinforcing elements 402 directly to the right of winding 410).

A winding pitch of a coiled electrode wire may be any suitable amountsmaller than a winding pitch of coiled a coiled reinforcing element. Inthe example shown in FIG. 4 , winding pitch 416 of coiled reinforcingelements 402 is approximately two times the length of winding pitch 414of coiled electrode wires 404.

A winding pitch may be measured in any suitable manner. In certainexamples, when the electrode lead is viewed in a direction perpendicularto the length of the electrode lead, the winding pitch may be measuredfrom one side of a winding to the same side of a successive winding. Forexample, the winding pitch may be measured from a distal side of onewinding to a distal side of a successive winding of the same coiledreinforcing element. Alternatively, the winding pitch may be measuredfrom a center of a winding to a center of a successive winding whenviewed in the direction perpendicular to the length of the electrodelead. For example, winding pitch 416 is a distance measured from adistalmost portion of a winding included in one group of windings to adistalmost portion of a winding included in a successive (i.e.,immediately adjacent) group of windings included in the plurality ofhelically formed groups of windings of coiled reinforcing elements 402.

As shown in FIG. 4 , a winding direction (indicated by arrow 418) ofcoiled reinforcing elements 402 is opposite a winding direction(indicated by arrow 420) of coiled electrode wires 404. For example,coiled reinforcing elements 402 are wound in a counterclockwisedirection whereas coiled electrode wires 404 are wound in a clockwisedirection. As explained above, such a configuration is desirable becausetorsion in a direction opposite to the winding direction of coiledelectrode wires 404 may cause coiled electrode wires 404 to get damagedor broken due to coiled electrode wires 404 being kinked. However, whencoiled reinforcing elements 402 are wound in a winding directionopposite the winding direction of coiled electrode wires 404, coiledreinforcing elements 402 provide a resistive force that prevents suchkinking of coiled electrode wires 404.

In certain examples, a coiled reinforcing element may be provided at adifferent distance in a radial direction from a longitudinally-extendingcenter axis of electrode lead 110 than a coiled electrode wire. Toillustrate, FIG. 5 depicts an enlarged cross-sectional view of electrodelead 110 taken along line 5-5 in FIG. 4 . As shown in FIG. 5 , coiledreinforcing elements 402 are provided at a first distance 502 in aradial direction (i.e., at a first radius) from longitudinally-extendingcenter axis 504 of electrode lead 110 whereas coiled electrode wires 404are provided at a second distance 506 in the radial direction (i.e., ata second radius) from longitudinally-extending center axis 504 ofelectrode lead 110. In the example shown in FIG. 5 , the first distance502 is greater than the second distance 506. However, in certain otherimplementations, first distance 502 may be smaller than second distance506 such that coiled reinforcing elements 402 are provided closer tolongitudinally-extending center axis 504 than coiled electrode wires404.

Coiled reinforcing elements such as those described herein may have anysuitable cross-sectional shape as may suit a particular implementation.In the example shown in FIG. 5 , coiled reinforcing elements 402 have acircular-shaped cross-section. However, in certain implementations acoiled reinforcing element may have, for example, a square, oval, orrectangular cross-sectional shape.

In addition, coiled reinforcing elements such as those described hereinmay have any suitable size (e.g., diameter) as may suit a particularimplementation. In certain examples, the diameter of a coiledreinforcing element may be less than 20-100 μm to avoid significantincrease in the size of flexible body 410 and to maintain sufficientflexibility of electrode lead 110.

In the example shown in FIG. 5 , coiled reinforcing elements 402, coiledelectrode wires 404, and coiled grounding wire 406 are embedded withinflexible body 408 such that coiled reinforcing elements 402 areseparated from coiled electrode wire 404 in the radial direction by aportion of flexible body 408.

In certain alternative examples, a coiled reinforcing element may bewrapped around a coiled electrode wire as opposed to being spaced apartfrom coiled reinforcing elements in the radial direction. When a coiledreinforcing element is wrapped around a coiled electrode wire, thecoiled reinforcing element may be in direct contact with at least someportions of the coiled electrode wire in the radial direction. Inaddition, when a coiled reinforcing element is wrapped around a coiledelectrode wire, each portion of the coiled reinforcing element may beprovided farther from longitudinally-extending center axis 504 ofelectrode lead 110 than the coiled electrode wire.

In certain examples, a coiled reinforcing element and a coiled electrodewire may be provided within a lumen of flexible body 408. In suchexamples, the lumen may be pre-formed in flexible body 408. The coiledreinforcing element and the coiled electrode wire may be wound withrespect to one another, such as described herein, and inserted withinthe lumen of flexible body 408 during manufacture of electrode lead 110.To illustrate, FIG. 6 shows an exemplary fantail region 304 of electrodelead 110 in which coiled electrode wires 404 and a plurality of coiledreinforcing elements 602 (“coiled reinforcing elements 602”) areprovided within a lumen 604 of flexible body 408.

In the example shown in FIG. 6 , coiled reinforcing elements 602 areprovided closer to longitudinally extending center axis 504 of electrodelead 110 than coiled electrode wires 404 such that each portion ofcoiled electrode wires 404 is provided farther fromlongitudinally-extending center axis 504 of electrode lead 110 thancoiled reinforcing elements 602. Although FIG. 6 shows coiled electrodewires 404 being provided around coiled reinforcing wires within lumen604, it is understood that in certain alternative examples a coiledreinforcing element may be provided around a coiled electrode wire andthe combination of the coiled reinforcing element and the coiledelectrode wire may then be inserted within lumen 604.

In the example shown in FIG. 6 , each coiled reinforcing elementincluded in coiled reinforcing elements 602 is bundled together so as toform a plurality of helically formed groups of windings extending alongthe length of flexible body 408. However, it is understood that incertain implementations a single coiled reinforcing element (e.g., asingle coiled ribbon, strand, fiber, etc.) may be provided closer tolongitudinally-extending center axis 504 of electrode lead 110 thancoiled electrode wires 404.

In the example shown in FIG. 6 , a winding pitch 606 of coiledreinforcing elements 602 corresponds to a distance between successivegroups of winding groups included in the plurality of helically formedgroups of windings of coiled reinforcing elements 602. Similar to theexample shown in FIG. 4 , winding pitch 414 of coiled electrode wires404 is smaller than winding pitch 606 of coiled reinforcing elements602. In addition, a winding direction of coiled electrode wires 404 isopposite a winding direction of coiled reinforcing elements 602.Although the example shown in FIG. 6 has been described as includinglumen 604, it is understood that, in certain examples, the configurationshown in FIG. 6 could be formed without including lumen 604. Forexample, coiled reinforcing elements 602, coiled electrode wires 404,and coiled grounding wire 406 may be placed in an electrode lead moldand a flexible insulating material may be provided in any suitablemanner within the electrode lead mold such that the flexible insulatingmaterial surrounds coiled reinforcing elements 602, coiled electrodewires 404, and coiled grounding wire 406.

FIG. 7 shows an alternative implementation in which a plurality ofcoiled reinforcing elements (e.g., a first coiled reinforcing element702, a second coiled reinforcing element 704, a third coiled reinforcingelement 706, etc.) are implemented as separate strands that are woundalong the length of flexible body 408 without crossing over one another.As shown, the coiled reinforcing elements are spaced apart from eachother by approximately the same distance 708 along flexible body 408.

First coiled reinforcing element 702, second coiled reinforcing element704, and third coiled reinforcing element 706 are separate strands fromone another that are wound along the length of flexible body 408 withoutcrossing over one another (i.e., the separate strands are not braidedtogether). Because of this, in the example shown in FIG. 7 , there are aplurality of windings of other coiled reinforcing elements (e.g., secondcoiled reinforcing element 704, third coiled reinforcing element 706,etc.) that are provided between successive windings of first coiledreinforcing element 702. Similar to the example shown in FIG. 4 , awinding pitch 710 of each coiled reinforcing element (e.g., first coiledreinforcing element 702) is larger than winding pitch 414 of coiledelectrode wires 404. In addition, as shown in FIG. 7 , each of thecoiled reinforcing elements has a winding direction that is opposite awinding direction of coiled electrode wires 404.

In certain examples, a coiled reinforcing element may include only asingle strand that includes a plurality of helically formed windingsextending within flexible body 408. To illustrate, FIG. 8 shows anexemplary fantail region 304 of electrode lead 110 in which a singleribbon-shaped coiled reinforcing element 802 (“coiled reinforcingelement 802”) is provided. Although coiled reinforcing element 802 is inthe shape of a ribbon, it is understood that any other suitable shapefor a single strand reinforcing element may be used in certainimplementations. Similar to the example shown in FIG. 4 , a windingpitch 804 of coiled reinforcing element 802 is larger than winding pitch414 of coiled electrode wires 404. In addition, as shown in FIG. 8 ,coiled reinforcing element 802 has a winding direction that is oppositea winding direction of coiled electrode wires 404.

In certain examples, electrode lead 110 may include an additional coiledreinforcing element that has a winding direction opposite to the windingdirection of coiled reinforcing element 402. To illustrate, FIG. 9 showsan exemplary fantail region 304 of electrode lead 110 in which aplurality of additional coiled reinforcing elements 902 (“coiledreinforcing elements 902”) are provided together with coiled reinforcingelements 402. In the example shown in FIG. 9 , coiled reinforcingelements 902 are bundled together so as to form a plurality of groups ofhelically formed windings. As shown in FIG. 9 , coiled reinforcingelements 902 are wound in a clockwise direction whereas coiledreinforcing elements 402 are wound in a counterclockwise direction.Accordingly, the winding direction of coiled reinforcing elements 902 isopposite the winding direction of coiled reinforcing elements 402.

When such an additional coiled reinforcing element is provided withinflexible body 408, the additional coiled reinforcing element may alsohave a winding pitch that is larger than coiled electrode wires 404. Forexample, FIG. 9 shows that coiled reinforcing elements 902 have awinding pitch 904 that is approximately two times larger than windingpitch 414 of coiled electrode wires 404.

Although only fantail region 304 is illustrated in FIGS. 4-9 , it isunderstood that one or more coiled reinforcing elements, such as thosedescribed herein, may extend along any portion of electrode lead 110 asmay suit a particular implementation. For example, coiled reinforcingelements 402 shown in FIG. 4 may only be provided in a portion ofelectrode lead 110 (e.g., only in fantail region 304). Alternatively,coiled reinforcing elements 402 may extend substantially along theentire length of electrode lead 110 (e.g., so as to include fantailregion 304, distal region 306, and any portion of electrode lead 110therebetween). Additionally or alternatively, coiled reinforcingelements 402 may extend proximally into cochlear implant 108 togetherwith the electrode wires (e.g., inside the portion of cochlear implant108 illustrated in FIG. 4 ).

Although the various examples of electrode leads described herein areprovided in the context of a cochlear implant system, it is understoodthat principles such as those described herein could be applied to anytype of electrode lead where it may be desirable to increase themechanical strength of the electrode lead and prevent damage to anelectrode wire included in the electrode lead.

FIG. 10 illustrates a method 1000 for manufacturing a reinforcedelectrode lead (e.g., electrode lead 110). While FIG. 10 illustratesexemplary operations according to one embodiment, other embodiments mayomit, add to, reorder, and/or modify any of the operations shown in FIG.10 .

In operation 1002, an electrode wire is wound in a first windingdirection to form a coiled electrode wire. The electrode wire may bewound in any suitable manner. For example, the electrode wire may bewound around a mandrel to form a plurality of helically formed windings.Operation 1002 may be performed in any of the ways described herein.

In operation 1004, the electrode wire is attached to an electrodecontact (e.g., one of electrodes 112). The electrode wire may beattached in any suitable manner. For example, an electrode wire may bewelded to each electrode contact included in a plurality of electrodecontacts. Operation 1004 may be performed in any of the ways describedherein.

In operation 1006, a reinforcing element is wound in a second windingdirection to form a coiled reinforcing element. The second windingdirection is opposite the first winding direction. The reinforcingelement may be wound in the second winding direction in any suitablemanner. In certain examples, the reinforcing element may be wound in thesecond winding direction around a mandrel to form a plurality ofhelically formed windings. Alternatively, the winding of the reinforcingelement in the second winding direction may include winding thereinforcing element around the coiled electrode wire. In addition, thewinding of the reinforcing element may be performed such that a windingpitch of the coiled reinforcing element is larger than a winding pitchof the coiled electrode wire. Operation 1006 may be performed in any ofthe ways described herein.

In certain examples, operation 1006 may be performed prior to operation1002 such that the reinforcing element is wound in the second windingdirection prior to the electrode wire being wound in the first windingdirection. In such examples, the electrode wire may be wound around thereinforcing element instead of being wound around a mandrel.

In operation 1008, the coiled electrode wire, the electrode contact, andthe coiled reinforcing element are placed in an electrode lead mold suchthat the coiled reinforcing element extends longitudinally together withthe coiled electrode wire. Operation 1008 may be performed in any of theways described herein.

In operation 1010, the electrode lead mold is provided with a flexibleinsulating material (e.g., silicone) such that the coiled electrodewire, the electrode contact, and the reinforcing element are embeddedwithin the flexible insulating material. The electrode lead mold may beprovided with the flexible insulating material in any suitable manner.In certain examples, the flexible insulating material may be injectedinto the electrode lead mold such that such that the flexible body isformed when the flexible insulating material solidifies. In suchexamples, the flexible insulating material embeds the coiled reinforcingelement, the coiled electrode wire, and the electrode contact.Alternatively, the flexible insulating material may be compressionmolded in the electrode lead mold (e.g., by providing the flexibleinsulating material in a first half of the electrode lead mold and thenpressing a second half of the electrode lead mold onto the flexibleinsulating material provided in the first half of the electrode leadmold). Operation 1010 may be performed in any of the ways describedherein.

In certain alternative examples, a method for manufacturing a reinforcedelectrode lead (e.g., electrode lead 110) may include utilizingpre-manufactured reinforced tubing (e.g., silicone tubing) that isobtained from a tubing manufacturer and that already has a coiledreinforcing element embedded therein. FIG. 11 illustrates a method 1100for manufacturing a reinforced electrode lead (e.g., electrode lead 110)according to such alternative examples. While FIG. 11 illustratesexemplary operations according to one embodiment, other embodiments mayomit, add to, reorder, and/or modify any of the operations shown in FIG.11 .

In operation 1102, an electrode wire is attached to an electrode contact(e.g., one of electrodes 112). The electrode wire may be attached in anysuitable manner. For example, an electrode wire may be welded to eachelectrode contact included in a plurality of electrode contacts.Operation 1102 may be performed in any of the ways described herein.

In operation 1104, an electrode contact array area is molded with aflexible insulating material. The electrode contact array area may bemolded in any suitable manner. For example, silicone may be provided inany suitable manner with respect to a plurality of electrode contacts toform the electrode contact array area. Operation 1104 may be performedin any of the ways described herein.

In operation 1106, the electrode wire is wound in a first windingdirection to form a coiled electrode wire. The electrode wire may bewound in any suitable manner. For example, the electrode wire may bewound around a mandrel to form a plurality of helically formed windings.Operation 1106 may be performed in any of the ways described herein.

In operation 1108, the coiled electrode wire is covered withpre-manufactured reinforced tubing (e.g., silicone tubing). Thepre-manufactured reinforced tubing may be provided so as to cover thecoiled electrode wire in any suitable manner. For example, the coiledelectrode wire may be inserted into a lumen of the pre-manufacturedreinforced tubing. The pre-manufactured reinforced tubing includes areinforcing element that is embedded within a wall of the of thepre-manufactured reinforced tubing and that is wound in a second windingdirection is opposite the first winding direction. In addition, thereinforcing element in the pre-manufactured reinforced tubing has awinding pitch that is larger than a winding pitch of the coiledelectrode wire. Operation 1108 may be performed in any of the waysdescribed herein.

In operation 1110, the pre-manufactured reinforced tubing is providedwith a flexible insulating material (e.g., silicone) such that thecoiled electrode wire is embedded within the flexible insulatingmaterial. The flexible insulating material may be provided in anysuitable manner. For example, the flexible insulating material may beinjected within a lumen of the pre-manufactured reinforced tubing suchthat the flexible insulating material fills the lumen and embeds thecoiled electrode wire when the flexible insulating material solidifies.Operation 1110 may be performed in any of the ways described herein.

In the preceding description, various exemplary embodiments have beendescribed with reference to the accompanying drawings. It will, however,be evident that various modifications and changes may be made thereto,and additional embodiments may be implemented, without departing fromthe scope of the invention as set forth in the claims that follow. Forexample, certain features of one embodiment described herein may becombined with or substituted for features of another embodimentdescribed herein. The description and drawings are accordingly to beregarded in an illustrative rather than a restrictive sense.

What is claimed is:
 1. An electrode lead adapted for insertion into ahuman body, comprising: a flexible body formed of a flexible insulatingmaterial and that comprises a fantail region that connects to a cochlearimplant configured to be implanted within a recipient and that extendsto a ground electrode located toward a proximal end of the electrodelead; an electrode contact disposed on a side of the flexible body; acoiled electrode wire provided within the flexible body so as to extendalong a length of the flexible body and electrically connect theelectrode contact to a signal source; and a coiled reinforcing elementprovided within the flexible body so as to extend together with thecoiled electrode wire along the length of the flexible body, wherein thecoiled reinforcing element is only provided within a proximal portion ofthe electrode lead.
 2. The electrode lead of claim 1, wherein the coiledreinforcing element is only provided in the fantail region of theflexible body that is in the proximal portion of the electrode lead. 3.The electrode lead of claim 1, wherein: a winding direction of thecoiled electrode wire is opposite a winding direction of the coiledreinforcing element; and a winding pitch of the coiled electrode wire issmaller than a winding pitch of the coiled reinforcing element.
 4. Theelectrode lead of claim 3, wherein: the coiled electrode wire includes aplurality of helically formed windings extending along the length of theflexible body; the winding pitch of the coiled electrode wirecorresponds to a distance between successive windings included in theplurality of helically formed windings; the coiled reinforcing elementincludes a plurality of additional helically formed windings extendingalong the length of the flexible body; and the winding pitch of thecoiled reinforcing element corresponds to a distance between successivewindings included in the plurality of additional helically formedwindings.
 5. The electrode lead of claim 3, wherein: the coiledelectrode wire includes a plurality of coiled electrode wires; eachcoiled electrode wire included in the plurality of coiled electrodewires is bundled together so as to form a plurality of helically formedgroups of windings extending along the length of the flexible body; andthe winding pitch of the coiled electrode wire corresponds to a distancebetween successive groups of windings included in the plurality ofhelically formed groups of windings.
 6. The electrode lead of claim 3,wherein: the coiled reinforcing element includes a plurality of coiledreinforcing elements; each coiled reinforcing element included in theplurality of coiled reinforcing elements is bundled together so as toform a plurality of helically formed groups of windings extending alongthe length of the flexible body; and the winding pitch of the coiledreinforcing element corresponds to a distance between successive groupsof windings included in the plurality of helically formed groups ofwindings.
 7. The electrode lead of claim 3, wherein: the coiledreinforcing element includes a plurality of coiled reinforcing elements;each coiled reinforcing element included in the plurality of coiledreinforcing elements includes a plurality of helically formed windingsextending along the length of the flexible body; successive helicallyformed windings included in the plurality of helically formed windingsare spaced apart from each other by a same distance along the length ofthe flexible body; and the winding pitch of the coiled reinforcingelement corresponds to a distance between helically formed windingsincluded in the plurality of helically formed windings of a particularcoiled reinforcing element included in the plurality of coiledreinforcing elements.
 8. The electrode lead of claim 3, wherein: thecoiled reinforcing element comprises a single ribbon that includes aplurality of helically formed windings extending along the length of theflexible body; and the winding pitch of the coiled reinforcing elementcorresponds to a distance between successive windings included in theplurality of helically formed windings of the single ribbon.
 9. Theelectrode lead of claim 1, wherein: the coiled reinforcing element isprovided at a first distance in a radial direction from alongitudinally-extending center axis of the electrode lead; the coiledelectrode wire is provided at a second distance in the radial directionfrom the longitudinally-extending center axis of the electrode lead; andthe first distance is greater than the second distance.
 10. Theelectrode lead of claim 1, wherein: the coiled reinforcing element isprovided at a first distance in a radial direction from alongitudinally-extending center axis of the electrode lead; the coiledelectrode wire is provided at a second distance in the radial directionfrom the longitudinally-extending center axis of the electrode lead; andthe first distance is smaller than the second distance.
 11. Theelectrode lead of claim 1, further comprising an additional coiledreinforcing element that has a winding direction opposite to a windingdirection of the coiled reinforcing element.
 12. The electrode lead ofclaim 1, wherein the coiled reinforcing element is embedded within theflexible body.
 13. The electrode lead of claim 1, wherein the coiledreinforcing element is wound around the coiled electrode wire.
 14. Theelectrode lead of claim 1, wherein: the flexible body includes a lumenthat extends along the length of the flexible body; and the coiledelectrode wire and the coiled reinforcing element are provided withinthe lumen of the flexible body.
 15. The electrode lead of claim 1,wherein the coiled reinforcing element is a polymer strand.
 16. Anelectrode lead adapted for insertion into a human cochlea, comprising: aflexible body formed of a flexible insulating material and thatcomprises a fantail region that connects to a cochlear implantconfigured to be implanted within a recipient and that extends to aground electrode located toward a proximal end of the electrode lead; aplurality of electrode contacts disposed on a side of the flexible body;a plurality of coiled electrode wires provided within the flexible bodyand that electrically connect the plurality of electrode contacts to asignal source, each coiled electrode wire included in the plurality ofcoiled electrode wires being bundled together so as to form a pluralityof helically formed groups of windings extending along a length of theflexible body; and a coiled reinforcing element provided within theflexible body and including a plurality of helically formed windingsextending along the length of the flexible body together with theplurality of helically formed groups of windings of the plurality ofcoiled electrode wires, wherein the coiled reinforcing element is onlyprovided within a proximal portion of the electrode lead.
 17. Theelectrode lead of claim 16, wherein: a winding pitch of the plurality ofcoiled electrode wires corresponds to a distance between successivegroups of windings included in the plurality of helically formed groupsof windings; and a winding pitch of the coiled reinforcing elementcorresponds to a distance between successive windings included in theplurality of helically formed windings of the coiled reinforcingelement.
 18. A method of manufacturing an electrode lead adapted forinsertion into a human body, the method comprising: winding an electrodewire in a first winding direction to form a coiled electrode wire;attaching the electrode wire to an electrode contact; winding areinforcing element in a second winding direction to form a coiledreinforcing element; placing the coiled electrode wire, the electrodecontact, and the coiled reinforcing element in an electrode lead moldsuch that the coiled reinforcing element extends longitudinally togetherwith the coiled electrode wire; and providing, after placing the coiledelectrode wire, the electrode contact, and the coiled reinforcingelement in an electrode lead mold, the electrode lead mold with aflexible insulating material such that the coiled electrode wire, theelectrode contact, and the reinforcing element are embedded within theflexible insulating material, wherein: the electrode lead includes afantail region that connects to a cochlear implant configured to beimplanted within a recipient and that extends to a ground electrodelocated toward a proximal end of the electrode lead; and the coiledreinforcing element is only provided within a proximal portion of theelectrode lead.
 19. The method of claim 18, wherein the winding of thereinforcing element in the second winding direction includes winding thereinforcing element around the coiled electrode wire.
 20. The method ofclaim 18, wherein: the flexible insulating material is silicone; and theproviding of the electrode lead mold with the flexible insulatingmaterial includes injecting the silicone into the electrode lead moldsuch that a flexible body is formed when the silicone solidifies.